UDF Parameters lookup

[G Gabriel]

Not sure if I dreamed this up, but I think there was a way to make it possible to lookup certain parameters (e.g. sets, tables, indices etc.) in a UDF.

Is there?

[Tom Cone Jr]

Re: UDF Parameters lookup

G, I'm not understanding the question. I suppose you're not asking about any of the lookup() functions, right? The parameters passed to a function are available to the function itself, of course, so you must not be talking about that either, right? So, what's the context in which you might want to "lookup certain parameters" ?

[Steve Workings]

Re: UDF Parameters lookup

Yes, you can do this. I've done it, it's buried in the help file someplace that I can't find right now, and Ira knows how to do it.

Tom - he's looking to provide some autocomplete help with the parameters in a UDF. For instance, if a tablename is selected, you can provide some dropdown-type/autocomplete select list of the indexes for that table, for instance.

Too busy to complete my search for this today and give you the answer, but I know you can do it.

If this is still unanswered tonight (I'm teaching all day) I'll look some more. I'd like more of my UDFs to have this feature and I need to get in better practice of using it.

[G Gabriel]

Re: UDF Parameters lookup

Thanks Steve..
I know it's there, in fact I did it before and for the life of me can't remeber where I found it in the help file nor willing to spend a whole lot of time looking right now.

Tom:
Steve explained it better than I did.

[G Gabriel]

Re: UDF Parameters lookup

I think I found it:
http://support.alphasoftware.com/alp...e/function.htm

[csda1]

Re: UDF Parameters lookup

Hi Steve,

Yes, you can do this. I've done it, it's buried in the help file someplace that I can't find right now, and Ira knows how to do it.

Unfortunately, it's undocumented and UNSUPPORTED! It is a real kludge and doesn't allow for different functions using the exact same parameter name (e.g. TableName) to have different help. On the other hand, if another system function already has parameter help the way you like it, then just name your parameter the same as that function's.

I had suggested to Selwyn back a couple of years ago to allow user supplied function help by specifying a line something like near the top of the code something like this

'ParameterHelp:Parameter1Name:UsersParameter1FunctiontoPopupHelp(pointer_to_current_function_parameter_values)
'ParameterHelp:Parameter2Name:UsersParameter2FunctiontoPopupHelp(pointer_to_current_function_parameter_values)

Alternatively, you can try my method for parameter help/prompting. It doesn't help when coding, but does help when using it. That is, when the parameter has a leading space (for characters or blobs), or is a NULL_VALUE() or other type that is not supported, I pop up a dialog with selections for that parameter. For number fields that are not negative, I often use a negative value to force the prompt, converting the absolute value as the default).

This makes it very easy to use the functions in the interactive window or when you want it to prompt you. The default value for the dialog is always the substr(parameter,2) value(s), or abs(parameter) for numeric types.

Most of my released functions do this, and I have updated just about all of my code to invoke this through a simple standardized XDialog function I created. Thus, with 1 line of code and some help text passed to it, I get a very useful menu selection

[Steve Workings]

Re: UDF Parameters lookup

Actually, you reminded me Ira, though mostly in passing, how to do the simplest of this.

For anyone who cares, build this function:

FUNCTION TestPrompt AS f (tablename AS C )
	msgbox("tablename is", tablename)
END FUNCTION

Then, when you use it, because you specified tablename, you get the "usual" behavior from Alpha to find a table name.

You can look at any function in Alpha, such as lookupc() where tablename is one of the parameters, to see how this would perform.

Here's another example:

FUNCTION SelectLayout AS F (layoutname AS C )
	msgbox("Selected Layout is", layoutname)
END FUNCTION

Here, the use of the layout parameter behaves the same way it does when, for example, you're writing the report.preview() instruction.

This doesn't completely accomplish what Ira is suggesting or give us the kind of flexibility that would be nice to have, but does offer a bit of standard help to UDF users.

[MikeC]

Re: UDF Parameters lookup

Ira and all,
By coincidence I have been doing just what is being asked for here in a UDF I am creating.

A couple of things. As Ira indicated, if you use the same argument name as an existing Alpha function, your UDF will utilize the same feature as Alpha's. You can be more descriptive also in that say the Alpha argument is "tablename". If you name your argument "First_tablename", "Last_tablename" or whatever prefix you want with an underscore in front it will use the Alpha argument's feature, in this case, of course, a crlf list of all the tables in the database.

Also with the function bubblehelp Selwyn posted on the board and which I had also posted more recently, you can create you own with the addin.function_argument_help(). I recently added 2 more addins to the list--ui_get_filter() and ui_get_order(). I am having a bit of problem being able to pass some variables to this UDF in order to have different tables/sets appear....this particular UDF will have the capability of passing one set and 3 tables along with each of the table's fields as dropdown lists. Will that is if I can get it to readily accept my variables for the various tables which is needed to then bring up the specific table's fields.

:)

I will have to check out that help page that G posted as well--seems to be on the same sort of path as the addin argument.

Cal Locklin helped out as far as making the help under the function appear--the trick is to create an AEX and import it to your Library (database specific) or add it to the Alpha install directory folder called "addins installed".

Any takers on how to pass the various table names (variables) to the fieldname arguments so to have them give the corresponding table's fieldnames instead of just the first tablename argument?? :)


EDIT___Ira, Could you explain just a bit more regarding your work-around for this--may just work a bit better maybe...or used in conjunction with what I am currently doing.

[Lance Gurd]

Re: UDF Parameters lookup

Got this a while ago, can't remember where from, hope it helps

[csda1]

Re: UDF Parameters lookup

You can be more descriptive also in that say the Alpha argument is "tablename". If you name your argument "First_tablename", "Last_tablename" or whatever prefix you want with an underscore in front it will use the Alpha argument's feature, in this case, of course, a crlf list of all the tables in the database.

Nice find. However, it could be annoying if that was not the intended parameter prompt.

Also with the function bubblehelp Selwyn posted on the board and which I had also posted more recently, you can create you own with the addin.function_argument_help(). I recently added 2 more addins to the list--ui_get_filter() and ui_get_order(). I am having a bit of problem being able to pass some variables to this UDF in order to have different tables/sets appear....this particular UDF will have the capability of passing one set and 3 tables along with each of the table's fields as dropdown lists. Will that is if I can get it to readily accept my variables for the various tables which is needed to then bring up the specific table's fields.

:)

I will have to check out that help page that G posted as well--seems to be on the same sort of path as the addin argument.

Cal Locklin helped out as far as making the help under the function appear--the trick is to create an AEX and import it to your Library (database specific) or add it to the Alpha install directory folder called "addins installed".

Any takers on how to pass the various table names (variables) to the fieldname arguments so to have them give the corresponding table's fieldnames instead of just the first tablename argument?? :)

You can create your own code to prompt for the parameter's help, and then use the special parameters below in the code that calls it.
%lastvalue%
%tablename%
%thisobject%
%system_mode%
%functionname%
I believe they are current values from other parameter fields you have set elsewhere in the parameter line.

Ira, Could you explain just a bit more regarding your work-around for this--may just work a bit better maybe

Take a look at this sample code. There is more that I do, but this is the basic methodology.

'Date Created: 03-Oct-2008 08:54:53 AM
'Last Updated: 03-Oct-2008 09:01:50 AM
'Created By  : Ira J. Perlow
'Updated By  : Ira J. Perlow
FUNCTION FunctionParameterPrompts AS C (Character_Parameter="" as C, Numeric_Parameter=0 as N)
'DESCRIPTION: This is the description popup line for FunctionParameterPrompts
' You may have to restart Alpha Five for the above to appear or to show current changes



'=========================================================================
' Created by Computer Systems Design & Associates
' Created October 3, 2008
' http://www.csda1.com
'=========================================================================
' Sample inteactive usages
'    ?FunctionParameterPrompts(" GlobalFunctionName", -5)
'    ?FunctionParameterPrompts(" GlobalFunctionName", 4)
'    ?FunctionParameterPrompts("GlobalFunctionName", -6)
'    ?FunctionParameterPrompts("GlobalFunctionName", 7)
'    ?FunctionParameterPrompts("GlobalFunctionName")
'    ?FunctionParameterPrompts(" GlobalFunctionName")
'    ?FunctionParameterPrompts(" ")
'    ?FunctionParameterPrompts()

' Process input parameters
dim chrprm as c
IF Left(Character_Parameter,1)==" "
    ' A leading space on this parameter means we want to prompt for value
    chrprm=SUBSTR(Character_Parameter,2)    ' Default value to use without leading space

    ' Prompt for Character Parameter starting with 2nd character.
    ' Normally a more extensive XDialog box
    chrprm=ui_get_list2("List Dialog",chrprm,a5.Udf_Enum(2),1)
    IF chrprm==""
        EXIT FUNCTION    ' Exit if dialog box was cancelled
    END IF    
ELSE IF Character_Parameter==""
    ' Null parameter can be used to set default value, such as 
    ' (DO ONLY 1 OF THE BELOW)
        '------------------------------------------------------
        ' set to XYZ, 
        chrprm="xyz"
        '------------------------------------------------------
        ' leave as a null value ""
        chrprm=""
        '------------------------------------------------------
        ' or do something special, e.g. display some help text
        dim HelpText as c
        HelpText=<<%text%
This is Help Text for the function FunctionParameterPrompts
To use this function......
        %text%
        ui_msg_box("FunctionParameterPrompts",HelpText,UI_OK)
        EXIT FUNCTION
        '------------------------------------------------------
ELSE
    ' Otherwise use the parameter as given
    chrprm=Character_Parameter
END IF

dim numprm as n
IF Numeric_Parameter<0
    ' A negative number on this parameter means we want to prompt for value
    numprm=abs(Numeric_Parameter)    ' Default value to use

    ' Prompt for Numeric Parameter
    ' Normally a more extensive XDialog box
    choice=ui_get_number("Number Dialog","Enter number",ltrim(str(numprm)))
    IF choice==""
        EXIT FUNCTION    ' Exit if dialog box was cancelled
    END IF    
    numprm=val(choice)
    ' we could loop back to dialog if value is not valid
ELSE IF Numeric_Parameter=0
    ' Null parameter can be used to set default value, such as 
        ' 5 
        ' leave as 0 value
        ' or do something special, e.g. display some help text
    numprm=0
ELSE
    ' Otherwise use the parameter as given
    numprm=Numeric_Parameter
END IF

' Now do normal processing with modified values chrprm, numprm
FunctionParameterPrompts="Function Name: "+chrprm+", Number: "+LTRIM(STR(numprm))

EXIT FUNCTION

END FUNCTION

[MikeC]

Re: UDF Parameters lookup

Thanks Ira,

You can create your own code to prompt for the parameter's help, and then use the special parameters below in the code that calls it.
%lastvalue%
%tablename%
%thisobject%
%system_mode%
%functionname%
I believe they are current values from other parameter fields you have set elsewhere in the parameter line.

I have used these, but perhaps I just didn't use them correctly in this case--I am so close to finishing this UDF as far as the "guts" of it that I'm getting a bit anxious I think! :)

I will take a closer look at your parameter scripting to see if I understand/can use it for the purpose I need it for.

Thanks again.



G--what Lance attached is what I was referring to that I had reposted from I think was a 2002 post by Selwyn. From that, the syntax of quite a bit of the features wanted to be incorporated into a UDF can be ascertained.

[G Gabriel]

Re: UDF Parameters lookup

Thanks to all.

[CALocklin]

Re: UDF Parameters lookup

Ira's reference to this function as a "kludge" may be an understatement. Has anyone been able to get it to work? If so, how?

I tried the following. When I create a function that uses "MyTest" as an argument then try to use the function, it tells me to "right click..." for the list but it won't show me the list to select from. I think "Q" should work but I tried at least "", "Q", "A", "=", "=Q", "=A", "QA", "=QA", "=AQ".

(I tried a few other things as well but won't go into all the gory details.)

text_list = <<%list%
asdf
qwer
zxcv
%list%

addin.function_argument_help( "MyTest", "Cals Test", text_list, "Q", "" )

[MikeC]

Re: UDF Parameters lookup

Cal,
absolutely have!! :)

Almost done with my UDF that will take most of the necessary parameters I need for a simple project. So far have 11 of 12 working--will work on the 12th tonight yet. I have it bring up:

1 list of sets
5 lists of independent tables
5 lists of fieldnames corresponding to the tables, 2 of which bring up the Filter Builder and the Order Builder.

The last item is to bring a crlf list of static names.

I'll get something together to post if you want---but may be difficult as I have gone through a whole bunch of renditions of the UDF to get it to work and have a ton of extraneous code in it that may just confuse (others and me!)

[CALocklin]

Re: UDF Parameters lookup

I would definitely be interested in seeing something that works. Or, if you can explain what is required, that would be even better yet.

Looking at the examples that Selwyn gave it seems like it should be pretty easy. I wouldn't be surprised to find that it's something simple I'm overlooking. It certainly wouldn't be the first time that happened.

EDIT: I figure it out. And, sure enough, it was something simple I overlooked. The string itself must be enclosed in quotes. This did the trick:

text_list = <<%list%
asdf
qwer
zxcv
%list%

addin.function_argument_help( "MyTest", "Cals Test", [B][COLOR="Red"]"\""+[/COLOR][/B]text_list[B][COLOR="Red"]+"\""[/COLOR][/B], "Q", "" )